Field of the Invention
The present invention relates to a toner supply device with a toner-contained cartridge of the throwaway type, which is for supplying toner to a developing unit of an image forming apparatus, and more particularly to a toner supply device with a throwaway type cartridge having a spiral agitator.
The present invention also relates to a reserve tank in a toner dispensing section for supplying toner to a developing unit.
Additionally, the present invention relates to an empty detector of an image forming apparatus with a reserve tank which receives toner from a cartridge used being loaded to the apparatus, and more particularly to an empty detector for an image forming apparatus, which detects an empty condition of a reserve tank.
In a conventional toner supply device for supplying toner to a developing unit of a copying machine, a toner box is installed in a main body of a copying machine. Toner is supplied from the toner box to the developing unit by means of an auger. When toner is used up in the toner box, the toner box is pulled out to a toner supply position, and toner contained in a spare toner bottle is supplied to the toner box. The kinds of toner supplied are different for the types of the copying machines used. This makes servicing of the toner supply difficult and complicated. The toner supply servicing is usually done by a serviceman, for this reason.
The user must call a serviceman every time toner is used up. The user often encounters a situation where the user calls the serviceman, but he cannot quickly come for the toner supply service. The user then cannot use the copying machine until the serviceman arrives. This is very inconvenient for users.
In the toner supply servicing, the user often experiences that leaked toner drops fall on the floor on which the machine is located, or stick to clothes. Use of a cartridge filled with toner, in place of the conventional toner bottle, has been proposed. In the machine using the cartridge, when loaded to the machine, the cartridge is set to the toner box, and a cap is removed from the cartridge. When the cartridge is empty, the empty or old cartridge is removed and replaced by a new one. This proposal successfully solves the problem of soiling with the leaked toner. The toner supply servicing for the machine using the cartridge requires at least three actions; 1) to set the cartridge to the toner box, 2) to supply toner, and 3) to remove the cartridge. This is troublesome work. The serviceman call is still needed for the toner supply work. The problem as state above still remains unsolved.
If the user, layman, tries to replace the old toner cartridge with a new one, he will frequently make mistakes in the toner supply servicing. For example, a toner incompatible with the copying machine under use or an imitative toner may be set to the toner box of the machine.
Also in a case that the copying machine is left not used for a long time and accordingly toner is left in an immovable condition for a long time, the toner will make into lumps within the cartridge. The toner lumps may cause toner blocking.